My Pichu JUST Hatched And It Knows:
Pichu @Sooth Bell Lv.6 (Obviously In Training.)
Nature: Adamant (+Atk. -Sp.Atk.)
EV's: Unknown At The Moment...
How Does It Know This?
: http://static.gamesradar.com/images/mb/GamesRadar/us/Daily/2010/08-Aug/02/Top 7 births/Egg--article_image.jpg
it knows thunder and iron tail because the male pokemon you where breeding knows those two moves and pichu can learn them through tms.
hope I helped!
Most likely they were egg moves passed down from the father. Who did you breed?
Egg Moves from your Pikachu/Raichu. Simple as that.
Because those are moves pichu can learn. And because one of the Parents probably knew those moves it was passed down to pichu. simple as that